Apparatus for continuous measuring of the moisture content in a high temperature chamber at atmospheric pressure

ABSTRACT

The wet bulb thermometer of a psychrometer comprises a measuring portion mounted within a permeable sleeve which is high temperature resistant and which has a base portion extending outside the chamber containing the gaseous substance whose relative humidity is to be measured, the base portion being continuously traversed by flowing water so that the sleeve is always wetted.

nited States Patent Inventor Yukiyoski Kawaguchi Kyoto, Japan Appl. No.866,989 Filed Oct; 16, 1969 Patented Sept. 7, 1971 Assignee KabushikiKaisha Ichikin Kogyosha Kusatsu-shi, Shiga-ken, Japan Priority Nov. 14,1968 Japan 43/82845 APPARATUS FOR CONTINUOUS MEASURING OF THE MOISTURECONTENT IN A HIGH TEMPERATURE CHAMBER AT ATMOSPHERIC PRESSURE 9 Claims,5 Drawing Figs.

[15. Cl 73/29, 73/77, 73/338 1m. cl ..G01n 25/62, GOl n 25/56 [50] Fieldof Search 73/29, 77, 338, 338.3, 338.6

[56] References Cited UNITED STATES PATENTS 1,632,729 6/1927 Foote etal73/338.6X 3,191,313 6/1965 Moorhouse et al. 73/338 X 3,459,034 8/1969Kawaguchi 73/29 3,495,458 2/1970 Christensen 73/338.6

Primary Examiner-Richard C. Queisser Assistant Examiner-Ellis J. KochAttorney-waters, Roditi, Schwartz & Nissen ABSTRACT: The wet bulbthermometer of a psychrometer comprises a measuring portion mountedwithin a permeable sleeve which is high temperature resistant and whichhas a base portion extending outside the chamber containing the gaseoussubstance whose relative humidity is to be measured, the base portionbeing continuously traversed by flowing water so that the sleeve isalways wetted.

g a a s a a g 1 a a i a APPARATUS FOR CONTINUOUS MEASURING OF THEMOISTURE CONTENT IN A HIGH TEMPERATURE CHAMBER AT ATMOSPHERIC PRESSUREBRIEF SUMMARYDF THE INVENTION The invention relates to apparatus formeasuring the moisture content of a gaseous substance in a chamber athigh temperature and atmospheric pressure.

The measuring of the moisture content in a high temperature chamber atnormal pressure, especially continuously, has proven to be verydifficult, and it has been difficult to measure the wet bulb temperaturein an atmosphere above 100 C. with a conventional psychrometer.

Accordingly, conventional measuring is efiected in that a gaseoussubstance, whose moisture content is to be measured, within a hightemperature chamber is led from the chamber into a sampling chamber keptnear 100 C. and the wet bulb temperature at that time is known wherebythe moisture content thereof can be measured. In this conventionalarrange ment, it is very difficult to maintain the temperature of thesampling chamber constant with change of temperature in the hightemperature chamber and even if so adjusted, it takes considerable timebefore the temperature is stabilized, and there is caused delay inmeasurement and accordingly a com tinuous measurement isentirelyimpossible.

An object of the invention is to provide an apparatus in which the abovedefect, that is, the disadvantage of keeping the interior of thesampling chamber at a predetermined temperature can be overcome andthereby the moisture content of such a gaseous substance, within atreatment chamber for a web material or the like, that is about 250 C.at maximum, and which ranges from unsaturated to saturated conditions,can be continuously measured, and the apparatus is characterized in thata psychrometer with wet and dry bulb thermometers is provided in anatmosphere of the gaseous body to be measured, a measuring element forwet bulb temperature being detachably inserted in a sleeve made of ahigh-temperature-resistant capillary material the base portion of saidsleeve being exposed to the passage of water at a predetermined amountand at a predetermined pressure so that the sleeve is wetted thereby foralways being maintained in a predetermined wet condition.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a'diagrammatic illustrationof one embodiment of this invention;

FIG. 2 is a sectional side view of a portion of FIG. 1;

FIG. 3 is a sectional view taken along the line lIllIl in FIG. 2; and

FIGS. 4 and 5 are sectional views of modified versions of thearrangement of FIG. 2.

DETAILED DESCRIPT ION Referring to the drawing, numeral 1 denotes a hightemperature chamber at atmospheric pressure, and a dry bulb thermometer4 and a wet bulb thermometer 5 are provided at a measuring portion 3within the atmosphere of a gaseous body to be measured. The measuringportion 3 may be either at any position within the chamber 1 (notillustrated) or proximate the chamber 1 (as illustrated in FIG. 1) whenthe gaseous body within the chamber 1 is removed as a streaming currentby means of an exhaust fan 2.

At the wet bulb thermometer 5, there is provided as shown in FIG. 2 ahigh-temperatureresistant air-permeable sleeve 6. This sleeve 6 is soconstructed that a capillary material such as glass fiber, spongeplatinum, asbestos, pumice, carbide or the like is filled within a spacebetween inner and outer spaced wire nets 7 and the top end thereof isclosed. A measuring element 9 of the wet bulb thermometer 5 isdetachably inserted within sleeve 6 from the outside thereof. A baseportion of the sleeve 6 projects outside the measuring portion 3 so asto be positioned in a passage 10 in which water passes from bottom totop. The necessity of the inner and outer wire nets 7 depends on thekind of the capillary material 8. The supply pressure and the amount,that is, the flow rate of water in the water passage 10 through aconduit 11 is properly predetermined so that the inner and outersurfaces of the sleeve 6 can be always kept in a predetermined wetcondition to enable accurate readings of wet bulb temperature by themeasuring element 9.

The base portion of sleeve 6 is attached to the chamber wall through amouthpiece 12. In this case, there is a danger that the mouthpiece 12may be heated above C. by the high temperature of the interior of themeasuring portion 3 and the water contained in that portion of thesleeve 6 surrounded by the mouthpiece 12 will boil to produce bubbleswhich make measuring impossible. Accordingly, a heat-insulating plate 13is provided at the portion of the mouthpiece 12 attached to themeasuring portion 3 as shown in FIG. 2 to prevent heat transfer thereto.Alternatively, a pipe 14 for cooling water is mounted around theperiphery of the mouthpiece 12 as shown in FIG. 4, so as to reduce thetemperature thereof.

If the wet bulb temperature-measuring portion goes above C., bubbles areliable to be produced owing to external variations so that themaintaining of the predetermined wet condition becomes difficult. Thesebubbles, however, can be moved to the base portion for being removedinto the water passage 10 by inclining the sleeve 6 to direct its topend downward, as shown in FIG. 5. It has been found by experiment thatthis inclination angle a must be above 10.

Referring to FIG. 2, numeral 15 denotes a filter of wire net or the likesurrounding the outer surface of the sleeve 6, and this filter 15 servesto prevent any difficulty in measurement caused by foreign matteradhering to the outer surface of the sleeve 6.

According to this invention, the measuring element for the wet bulbtemperature, provided within an atmosphere of the gaseous body to bemeasured, is covered by a capillary material made as a sleeve and saidsleeve is always wetted in a predetermined wet condition, so that anaccurate measuring of wet bulb temperature can be always obtained evenwith temperature change within the high temperature chamber. Hence therequirement for the sampling chamber, as in the conventional case, isnot required and measuring can be effected continuously and simply.

What is claimed is:

I. In an apparatus for continuous measurement of the moisture content ofa gaseous substance in a high temperature chamber at atmosphericpressure wherein a psychrometer with wet bulb and dry bulb thermometersis provided within an atmosphere of the gaseous substance to bemeasured, an improvement comprising a measuring element for the wet bulbtemperature, a sleeve comprising spaced wire nets andhigh-temperatureresistant capillary material between said nets, saidmeasuring element being detachably inserted in said sleeve, said sleeveincluding a base portion extending outside said chamber, and means forpassing water over said base portion of said sleeve at a predeterminedwater pressure and at a predetermined flow rate for wetting the sleeveand maintaining the same always in a predetermined wet condition.

2. An improvement as claimed in claim 1 wherein said means for passingwater over said base portion of said sleeve comprises a water passage atsaid base portion and a water conduit connected to said passage forpassing water therethrough.

3. An improvement as claimed in claim 2 comprising a mouthpiece outsidesaid chamber supporting said base portion of the sleeve, and meansmounting said mouthpiece on said chamber.

4. An improvement as claimed in claim 3 comprising cooling meanssurrounding said mouthpiece to prevent overheating thereof by thegaseous substance in the chamber.

5. An improvement as claimed in claim 3 wherein said sleeve andmeasuring element are tilted downwardly such that the end of the sleeveremote from said base'portion is lower than said base portion.

6. An improvement as claimed in claim 3 wherein said sleeve has an endremote from said base portion which is closed.

7. An improvement as claimed in claim 3 comprising a filter surroundingsaid sleeve.

8. An improvement as claimed in claim 3 wherein said chamber includes achannel in which the gaseous substance continuously flows, saidmouthpiece and sleeve being mounted on said channel.

9. ln an apparatus for continuous measurement of the moisture content ofa gaseous substance in a high temperature chamber at atmosphericpressure wherein a psychrometer with wet bulb and dry bulb thermometersis provided within an atmosphere of the gaseous substance to bemeasured, an

improvement comprising a measuring element for the wet bulb temperature,a sleeve constituted of high-temperatureresistant capillary material,said measuring element being detachably inserted in said sleeve, saidsleeve including a base portion extending outside said chamber, meansfor passing water over said base portion of said sleeve at apredetermined water pressure and at a predetermined flow rate forwetting the sleeve and maintaining the same always in a predeterminedwet condition, a mouthpiece outside said chamber supporting said baseportion of the sleeve, means mounting said mouthpiece on said chamber,and heat insulation means within said chamber shielding the mouthpiecein the region of the base of the sleeve from heat effect of the gaseoussubstance in the chamber

1. In an apparatus for continuous measurement of the moisture content ofa gaseous substance in a high temperature chamber at atmosphericpressure wherein a psychrometer with wet bulb and dry bulb thermometersis provided within an atmosphere of the gaseous substance to bemeasured, an improvement comprising a measuring element for the wet bulbtemperature, a sleeve comprising spaced wire nets andhigh-temperature-resistant capillary material between said nets, saidmeasuring element being detachably inserted in said sleeve, said sleeveincluding a base portion extending outside said chamber, and means forpassing water over said base portion of said sleeve at a predeterminedwater pressure and at a predetermined flow rate for wetting the sleeVeand maintaining the same always in a predetermined wet condition.
 2. Animprovement as claimed in claim 1 wherein said means for passing waterover said base portion of said sleeve comprises a water passage at saidbase portion and a water conduit connected to said passage for passingwater therethrough.
 3. An improvement as claimed in claim 2 comprising amouthpiece outside said chamber supporting said base portion of thesleeve, and means mounting said mouthpiece on said chamber.
 4. Animprovement as claimed in claim 3 comprising cooling means surroundingsaid mouthpiece to prevent overheating thereof by the gaseous substancein the chamber.
 5. An improvement as claimed in claim 3 wherein saidsleeve and measuring element are tilted downwardly such that the end ofthe sleeve remote from said base portion is lower than said baseportion.
 6. An improvement as claimed in claim 3 wherein said sleeve hasan end remote from said base portion which is closed.
 7. An improvementas claimed in claim 3 comprising a filter surrounding said sleeve.
 8. Animprovement as claimed in claim 3 wherein said chamber includes achannel in which the gaseous substance continuously flows, saidmouthpiece and sleeve being mounted on said channel.
 9. In an apparatusfor continuous measurement of the moisture content of a gaseoussubstance in a high temperature chamber at atmospheric pressure whereina psychrometer with wet bulb and dry bulb thermometers is providedwithin an atmosphere of the gaseous substance to be measured, animprovement comprising a measuring element for the wet bulb temperature,a sleeve constituted of high-temperature-resistant capillary material,said measuring element being detachably inserted in said sleeve, saidsleeve including a base portion extending outside said chamber, meansfor passing water over said base portion of said sleeve at apredetermined water pressure and at a predetermined flow rate forwetting the sleeve and maintaining the same always in a predeterminedwet condition, a mouthpiece outside said chamber supporting said baseportion of the sleeve, means mounting said mouthpiece on said chamber,and heat insulation means within said chamber shielding the mouthpiecein the region of the base of the sleeve from heat effect of the gaseoussubstance in the chamber.